android - 从 ArrayAdapter 刷新 ListView

Question

我正在使用 ArrayAdapter 将我的数据从 ArrayList 绑定(bind)到我的 ListView 并且我使用 AlertDialog 将数据插入我的 Arraylist。我的问题是更改完成后我无法刷新我的 ListView。

代码

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.config_hidden);
    listView=(ListView) findViewById(R.id.hiddenList);
    xmlFileManager=new XmlFileManager(this);
    addNumber=(Button) findViewById(R.id.addNum);

    addNumber.setOnClickListener(new OnClickListener() {

        public void onClick(View arg0) {

            LayoutInflater factory = LayoutInflater.from(HiddenCall.this);
            final View alertDialogView = factory.inflate(R.layout.add_number, null);
            AlertDialog.Builder adb = new AlertDialog.Builder(HiddenCall.this);
            adb.setView(alertDialogView);
            adb.setTitle(R.string.dialog_title);
            adb.setIcon(R.drawable.phone);

            final AlertDialog alertDialog = adb.create();

            adb.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    numberToAdd=(EditText) alertDialogView.findViewById(R.id.numberToAdd);
                    String number = numberToAdd.getText().toString();
                    if(number.length()>0){
                        xmlFileManager.addNumberToXml(number , HIDDEN_NUMBER_TYPE);
                        adapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, xmlFileManager.getHiddenNumbers());
                        adapter.setNotifyOnChange(true);
                        adapter.notifyDataSetChanged();
                    }
                } });

            adb.setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    alertDialog.dismiss();
                } });
            adb.show();
        }
    });
    adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, xmlFileManager.getHiddenNumbers());
    adapter.notifyDataSetChanged();
    adapter.setNotifyOnChange(true);
    listView.setAdapter(adapter);
}

Answer 1

您每次都在实例化一个新的适配器。您需要做的是在单击监听器之前放置实例化适配器的行，然后在单击监听器中修改该适配器并在其上调用 notifyDataSetChanged()。您当然必须向适配器添加一些 setter 才能修改数据。

必须看起来像这样:

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.config_hidden);
listView=(ListView) findViewById(R.id.hiddenList);

//instantiate the adapter (just one time)
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, xmlFileManager.getHiddenNumbers());

//assign the adapter to the listview
listView.setAdapter(adapter);

xmlFileManager=new XmlFileManager(this);
addNumber=(Button) findViewById(R.id.addNum);

addNumber.setOnClickListener(new OnClickListener() {

    public void onClick(View arg0) {

        LayoutInflater factory = LayoutInflater.from(HiddenCall.this);
        final View alertDialogView = factory.inflate(R.layout.add_number, null);
        AlertDialog.Builder adb = new AlertDialog.Builder(HiddenCall.this);
        adb.setView(alertDialogView);
        adb.setTitle(R.string.dialog_title);
        adb.setIcon(R.drawable.phone);

        final AlertDialog alertDialog = adb.create();



        adb.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                numberToAdd=(EditText) alertDialogView.findViewById(R.id.numberToAdd);
                String number = numberToAdd.getText().toString();
                if(number.length()>0){
                    xmlFileManager.addNumberToXml(number , HIDDEN_NUMBER_TYPE);
                    //adapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, xmlFileManager.getHiddenNumbers());
                    //adapter.setNotifyOnChange(true);

                    //set the changed data
                    adapter.setData(xmlFileManager.getHiddenNumbers());

                    //notify that the model changed
                    adapter.notifyDataSetChanged();
                }
            } });

        adb.setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                alertDialog.dismiss();
            } });
        adb.show();
    }
});

//adapter.notifyDataSetChanged();
//adapter.setNotifyOnChange(true);